Investigation of the generalized Brewster angle effect in MoS2 thin films

The growing interest in two-dimensional materials is driven by both scientific curiosity in understanding their unique properties and the technological challenge of producing large-area, low-defect monolayers and bilayers for engineering their use in several applications. In optics, comprehensive characterization across a broad spectral range under controlled polarization conditions is essential. Among low-dimensional materials, graphene is by far the most well known and widely studied. Notably, its optical anisotropy induces shifts in the pseudo-Brewster angle when deposited on dielectric substrates under specific conditions, with the direction of the shift depending primarily on the spectral range and the number of layers. Molybdenum disulfide (MoS2) exhibits a behavior analogous to that of graphene, although its properties have been less explored. In this work, we start investigating the generalized pseudo-Brewster angle effect in commercially available MoS2 thin films deposited on bulk SiO2, covering a wide spectral range. Our study intends to examine how the interaction between film thickness, refractive index, interference, and light polarization collectively influences the pseudo-Brewster angle, more precisely described as the generalized Brewster angle, revealing characteristic shifts that provide deeper insights into light-matter interaction in coatings based on MoS2. Furthermore, we propose a novel method to determine the thickness of thin films MoS2 using reflectivity measurements, offering a rapid and non-invasive characterization technique. These findings advance the development of polarization-sensitive optical components and highlight the promising potential of MoS2 in photonic and optoelectronic applications.